Silicone products have good resistance to high temperature performance, it can usually be long-term work at 180 ℃ high temperature. Silicone rubber is also a long time to work at 250 ℃, instantaneous ability of more than 1,000 degrees Celsius. Silicone materials low temperature performance is good, generally at -55 ℃ still work. Some silicone rubber remains elastic at -110 ℃. Silicone materials have good electrical insulation properties, dielectric properties with temperature changes and dramatic change; dielectric constant with frequency increases to increase the value; and arc resistance, corona resistance, leakage; resistant to ozone, radiation, weather , flame retardant, it is extremely versatile. Press the following broad categories of organic silicon products, are briefly as part of the main purposes:
1. The silane coupling agent is a silane coupling agent type low molecular weight compound, a silicon atom is connected to one end of a variety of hydrolyzable chlorine or alkoxy, can be connected with inorganic hydrolysis; the other end with a variety of the organic phase effect of a functional group, such as an amino group, a vinyl group, a mercapto group, etc., a silane coupling agent so that organic and inorganic substances capable of bridging them. Common silane coupling agent has nearly 100 kinds. Such as glass fiber FRP will be treated with a coupling agent containing a vinyl group to improve wet strength. The current popularity of "green" tires on the extensive use of thiol-containing silane coupling agent; polyethylene vinyl trialkoxysilane crosslinked, its working temperature can be higher than ordinary polyethylene and polyvinyl chloride, suitable for hot water pipe, cable sheathing.
2. The silicone oil silicone oil containing single or different organic groups of low molecular weight silicone, can be made into a variety of different viscosity. Low surface tension of silicone oil, contact angle with water of a large, high-quality water-repellent material. Silicone oil viscosity-temperature coefficient is small, does not solidified at low temperature, high temperature and low temperature are both spacecraft aviation gyroscope oil, antifreeze and heat-resistant lubricating oil, hydraulic oil, instrument oil, base oil, and the vapor low pressure high vacuum diffusion pump oil. Or a modified silicone oil used in cosmetic formulations in recent years is growing rapidly. Silicone paint on the skin non-greasy, smooth feel comfortable, can be made into a variety of skin creams and the like.
3. According to the silicone rubber vulcanization mechanism, the silicone rubber can be divided into high-temperature vulcanized silicone rubber (HTV); RTV silicone rubber (RTV) molding and processing liquid silicone rubber (LSR), with heat, cold, ozone resistance, UV resistance, atomic oxygen resistance, overall performance characteristics of cosmic rays and waterproof, shockproof. LSR liquid silicone rubber (also known as silica gel) is a semiconductor chip and electronic devices and excellent potting protective material; light transmission rate up to 91% of the silicone gel is to require high temperature, high humidity, no yellowing of three aircraft intermediate co windscreen adhesive layer. LSR silicone rubber molds for casting engine parts. HTV and RTV production accounted for a large share of organic silicon products (usually accounts for 40% ~ 50%), HTV purposes broader than RTV. (1) RTV RTV silicone rubber curing at room temperature is generally low molecular weight hydroxy-terminated polysiloxane (107 gel), together with the catalyst, fillers and the like made of bi-component or single-component, easy to use and can be cured at room temperature silicone rubber, a variety of material such as glass, ceramic, metal, concrete and other good adhesion, the adhesive is applied to a large number of full-field glass curtain wall, aluminum doors and windows and other structural parts of the seal, as well as the family bathroom, toilets and other plugging and caulking. Important RTV silicone rubber-based ablative thermal conductivity thermal barrier coating of small, easy construction, for rocket nozzle and return-type space vehicle from ablative heat insulating material, but also make spacecraft components material. RTV silicone rubber flexible mold or a variety of artistic carved decorative building materials.
(2) HTV HTV high temperature vulcanized silicone rubber is a high molecular weight (400,000 to 800,000) polyorganosiloxane, adding reinforcing fillers and other additives, curing, forming a cross-linked rubber. High voltage transmission of HTV silicone rubber composite insulators, porcelain insulators not only weighs only 1/5 ~ 1/10, easy to use, and good tolerance flash performance, safe operation in high voltage power transmission grid. In such as carbon black as a conductive medium HTV silicone rubber gaskets used for key, the keyboard is used extensively for other mobile phones and computers; silicone rubber for the production of a large number of seals, gaskets, seals, industrial rubber roller, rubber shock absorption, insulation products, medical products. Silicone rubber insulated flame retardant wire and cable for high reliability warships, aircraft and other requirements of the occasion. Silastic physiologically inert, blood was easy disinfection and other characteristics, can be made of silicone rubber catheters can be implanted in the human body parts and a variety of silicone rubber can be used for a long time, cannula, hydrocephalus drainage tubes, peritoneal dialysis tubes, and artificial heart-lung machine blood transfusion pump tube. In addition silicone rubber air permeability, gas permeability of different different. The oxygen transmission rate is the highest, to do oxygen-enriched membrane, gas separation membranes in the synthetic polymer.
4. The silicone insulating material made of silicone resin because of good heat resistance and insulation properties belonging to H level, the volume of motor use it to produce a small, light weight, high reliability, short overheat, an overload situation will not burned. Silicone resins can be formulated 500 ℃ high temperature resistant paint; silicone-modified acrylic resin coating weather resistance, and water-repellent, stain-resistant, senior exterior paint. Silicone resin, silicone plastic can be used for aircraft engine resistance to high voltage, high current, arc-resistant micro switch. In short use of silicone materials is very extensive, the effect is very significant.
(C) Silicone Products Silicone products, many categories, can be divided into five categories, namely: 1 high-temperature vulcanized silicone rubber most commonly used are methyl vinyl silicone rubber, cold-phenyl silicone rubber, oil resistance, solvent resistance fluorosilicone rubber and nitrile silicone rubber, radiation resistant phenylene silicone rubber. For ease of use often mix formulated to provide to the user.
2. RTV silicone rubber according to the packaging in the form of two-component and one-component division. Is divided into two component methyl, phenyl, nitrile, silicone, fluorosilicone, phenylene points; single component is divided into deacidification type, alcohol type, oxime type, from amine, amide type off, off-one type.
3. The silicone oil silicone oil can be divided into methyl silicone oil, ethyl silicone oil, methylphenyl silicone oil, amino silicone oil, methyl hydrogen silicone oil, chlorophenyl silicone oil, fluoro silicone, nitrile silicone, long-chain alkanes silicone oil, diffusion pump oil and modified silicone oil. There is a class belonging to a great amount of silicone oil processing products, namely, silicone emulsions, such as fabric treatment agent is one example.
4. Press the silicone resin silicone resin composition can be divided into methyl silicone, methyl phenyl silicone resin and the like; divided according to form solvent-based, solvent-free. There are also made of silicone coating, molding powder and modified.
5. Press the functional classification of the silane coupling agent, silane coupling agent, there are vinyl silane, amino silane, epoxy silane, mercapto silane and methacryloxy silane.
